Display system with a flexible display

ABSTRACT

A display system includes a continuous flexible display, two book halves, two main display supports, and a movement synchronizing coupling. The two book halves is connected to each other via a hinge mechanism. The hinge mechanism has two hinges, and each hinge is rotatable about respective axis. Each of the two main display supports connects to one of the two book halves and is configured to support the flexible display. The coupling is connected to the two main display supports and rotating about a rotation axis that is parallel to the axis of hinge to enable a synchronized movement of the two main display supports.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation application of prior application Ser.No. 15/608,221, filed on May 30, 2017 which is a divisional applicationof prior application Ser. No. 14/586,792, filed on Dec. 30, 2014 whichhas issued as U.S. Pat. No. 9,696,763 on Jul. 4, 2017, which is adivisional application of prior application Ser. No. 13/569,080, filedon Aug. 7, 2012 which has issued as U.S. Pat. No. 8,971,031 on Mar. 3,2015, the entire disclosure of each of which is hereby incorporated byreference.

FIELD OF INVENTION

The present invention generally relates to flexible displays. Thepresent invention specifically relates to flexible displays providedwith display supports.

DESCRIPTION OF PRIOR ART

A number of product concepts have been developed for flexible/rollabledisplays with a pair of display supports mutually connected by a hingemechanism. Examples of these concepts are the ‘book’ and the ‘wrap’, a‘wrap’ concept is shown in WO 2008/054206 A2.

The ‘book’ concept is the simplest implementation of a rollable displaycomprising two hingeably connected supports with a continuous display.In the middle near the hinge mechanism is a hollow space to accommodatethe curved segment of the display in the situation where the ‘book’ isin the closed position. The display size is at most twice the size ofthe closed display system. In practice, it will be around 1.8× the sizedue to the bezel of the support halves needed around the display.

The ‘wrap’ concept comprises a display with two hingeably connectedsupports, wrapped in the closed position with its front side to theinside. In the known concept the display makes one complete turn aroundthe device body when wrapped. Therefore, the size of the display isabout twice the size of the device. For larger displays compared to thedevice body more turns are required, which adds mechanical complexity.

In these concepts each hinge mechanism comprises two hinges beingmutually located at a distance. In practice for these concepts a doublehinge mechanism is preferred above a single hinge mechanism. A doublehinge mechanism shows the advantage of a smaller width of the displaysystem (measured in closed position), whereas in the open position thehinge shafts are located below the flexible display. Each of the pair ofhinges is configured for substantially 90° rotation of a respective oneof the display supports, whereas the display supports are rotatablebetween a configuration for fixing the flexible display in a closedstorage position and a planar configuration for fixing the flexibledisplay in an open position. If during movement to the open position theuser rotates one of the display supports with respect to the hingemechanism over an angle substantially larger than the other displaysupport, this difference between the rotations can result in problemswith the flexible/rollable display in the area of the hinge mechanism.In this area locally the internal stress in the layers of the displaymay become too high and/or the display may be curved into a curvature ata too small radius. Such excessive stress and/or too small radiuscurvature creation may damage the display and decrease the lifetime ofthe display.

It is an object of the invention to prevent local excessive stress inthe flexible display as well as curvature at a too small radius duringmovement of the display between closed and open position. It is also anobject to improve the lifetime of the display.

DISCLOSURE OF THE INVENTION

According to one aspect the invention provides a display systemcomprising:

a continuous flexible display,

at least two frame parts, each housing a main display support, saidsupports being hingable with respect to each other and each structurallyconfigured to support a respective portion of the flexible display,wherein the two main display supports are rotatable in oppositedirections, connected to each other by a hinge mechanism comprising twohinges being mutually located at a distance, each of the hinges beingconfigured for rotation of a respective one of the main displaysupports, the main display supports being rotatable between aconfiguration for fixing the flexible display in a closed storageposition and a planar configuration for fixing the flexible display inan open position, wherein the two main display supports are coupled toeach other by a movement synchronizing coupling, said coupling enablingduring movement between the closed and open position a mutualsubstantially synchronized rotating of the main display supports atsubstantially equal but oppositely directed angles.

Due to this synchronized rotating of the main display supports atsubstantially equal angles, excessive local stress in the display and/ora curvature at a too small radius in the display will be prevented, thusimproving the lifetime of the display. Another advantage of the displaysystem in accordance with the invention is the comfortable synchronizedmovement of both display supports, giving the user the feeling ofopening with rotation around only one hinge. A further advantage is thestable positioning of the main display supports in the open and closedposition, making additional locking action superfluous for the user inthese positions of the display system.

According to another aspect the invention provides a display systemwherein the movement synchronizing coupling that comprises spring meansproviding spring forces on both main display supports to move thedisplay system into the open or closed position respectively. Preferablythe spring means are part of an over center mechanism that, due to thespring force after movement to the open respectively closed endposition, stably positions the display system in either end position.

According to another aspect of the invention the movement synchronizingcoupling comprises at least one pair of wheels arranged near the hingemechanism, each being connected with a display support, said wheelsbeing mutually coupled for rotation in opposite directions.

In a preferred embodiment the movement synchronizing coupling is coupledwith at least one additional display support, configured to supportsubstantially a segment of the flexible display located between the saidrespective portions of the flexible display in the open position, saidadditional display support being movable by the coupling with themovement synchronizing coupling with respect to the display segmentbetween a non-operational position and a support position when the twomain display supports are moved between the storage position and theopen position of the flexible display, such that in the open positionsubstantially the whole surface of the display is supported by therespective display supports.

Reference is made to the non pre-published U.S. application 61/506,177,filed Jul. 11, 2011, (herewith incorporated by reference).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a first ‘book’ embodiment in an openposition, in accordance with the invention;

FIG. 2 shows a cross sectional view of the ‘book’ embodiment of FIG. 1in an open position;

FIG. 3 shows a cross sectional view of the ‘book’ embodiment of FIG. 1in a closed position;

FIG. 4 shows a perspective view of a second ‘book’ embodiment in aclosed position, accordance with the invention;

FIG. 5 shows a perspective view of part of the ‘book’ embodiment of FIG.4 in an open position;

FIG. 6 shows a side view of part of the ‘book’ embodiment of FIG. 4 inan open position;

FIG. 7 shows a side view of part of the ‘book’ embodiment of FIG. 4 in aclosed position;

FIGS. 8a-8f show a perspective view and a schematic side view of another‘book’ embodiment in an open position (FIG. 8 a/b), a partial openposition (FIG. 8 c/d) and a storage position (FIG. 8 e/f), respectively,in accordance with the invention;

FIGS. 9a-9b show a schematic view of a part of another ‘book’ or ‘wrap’embodiment in a side view (FIG. 9a ) and a top view (FIG. 9b ),respectively, in accordance with the invention;

FIGS. 10, 11 show a schematic side view of part of two other ‘book’ or‘wrap’ embodiments in a closed position, in accordance with theinvention; and

FIGS. 12a-12g show a perspective view of another ‘book’ embodiment in anclosed position (FIG. 12a ), in an open position (FIG. 12b ), as well asa view of parts of the movement synchronizing coupling in thisembodiment (FIGS. 12c-12g ) in accordance with the invention.

DETAILED DESCRIPTION

The embodiment shown in FIG. 1 is a ‘book’ display system 1 with twobook halves, comprising a flexible display 2, extending continuouslyover both halves and a support frame, comprising in each of the bookhalves a main display support 3, 4 respectively, being connected at bothsides of the system 1 by hinges 5, 6, respectively, of a hinge mechanism7 and each being structurally configured to support a respective portionof the flexible display 2. As shown in FIGS. 2 and 3, the two maindisplay supports 3, 4 are mutually hingable around their hinges 5, 6between a planar configuration (FIG. 2) for fixing the flexible display2 in an open position and a configuration for fixing the flexibledisplay in a closed storage position (FIG. 3).

Between the respective hinge 5, 6 and the respective display support 3,4 first additional display supports 8, 9, are configured rotatablyaround axes 8 a, 9 a and connected with the display support 3, 4.Between the pair of first additional display supports 8, 9 a second pairof additional display supports 10, 11 are arranged linked with a centraladditional display support 12 and rotatable around the axis 5, 6respectively. Together, the additional display supports 8, 9, 10, 11 and12 in the open position close the gap created by the hinge mechanism 7between the main supports 3, 4. Thus in the open position substantiallythe whole surface of a central display segment 2 a located between thedisplay supports 3, 4 is supported. These additional display supports 8,9, 10, 11 and 12 are movably arranged in the support frame of thedisplay system 1 with respect to the central display segment 2 a betweena non-operational position and a support position when the two maindisplay supports 3, 4 are moved between the storage position and theopen position of the flexible display.

In accordance with the present invention the two main display supports3, 4 are coupled to each other by a movement synchronizing coupling,enabling during movement between the closed and open position a mutualsubstantially synchronized rotating of the main display supports 3, 4 atsubstantially equal but oppositely directed angles.

This movement synchronizing coupling comprises at both sides of thesupport frame a pair of cams 13, 14, rotatably mounted in the supportframe around axes 13 a, 14 a, extending substantially parallel with theaxes 5, 6. The cams are coupled with the first pair of additionaldisplay supports 8, 9 and a pair of levers 15, 16, coupled with thecentral additional display support 12. During movement of the maindisplay supports 3, 4 from the position shown in FIG. 3 towards the openposition of FIGS. 1, 2, the central display support is lifted up and atthe same time the two linked additional supports 10, 11 are turned downaround the axis 5, 6 respectively. The additional display supports 8, 9are turned up around their axes 8 a, 9 a respectively and are pushedupwardly and are stably positioned in the open position of FIG. 2 bynotches 13 b, 14 b at the cams 13, 14. All moving parts are moved to thesame level to support the display segment 2 a. During movement to theclosed position of FIG. 3 the supports 3, 4 are closed, the centralsupport 12 is moved down, the two additional supports 10, 11 are turnedup and the other supports 8, 9 are turned down. All moving parts aremoved away from the centre bottom area to increase space for the foldingdisplay storage (see FIG. 3). The movement synchronizing coupling of thecams 13, 14, the supports 8, 9, 10, 11, 12 and the levers 15, 16 enablein an effective way a mutual substantially synchronized rotating of themain display supports 3, 4 at substantially equal but opposite anglesand synchronized movement of the additional display supports 8, 9, 10,11 and 12 between their support position and non-operational position.

Due to this synchronized rotating of the main display supports atsubstantially equal angles, excessive local stress in the display and/ora too small radius of curvature in the display will be prevented, thusimproving the lifetime of the display. Another advantage of the displaysystem in accordance with the invention is the comfortably synchronizedmovement of both display supports, giving the user the feeling ofopening with rotation around only one hinge. A further advantage is thestable positioning of the main display supports in the open and closedposition, making additional locking actions superfluous for the user inthese positions of the display system.

In the storage position of the flexible display 2 shown in FIG. 3,between the main display supports 3, 4 and the additional displaysupports 8, 9, 10, 11 and 12 there is sufficient free space for enablinga partial curvature of the display segment 2 a without conflicting withthe respective main display supports.

In the open position between display supports 3, 4 the display segment 2a is supported by the additional supports when touched. This means thatdamage of the display is prevented when touch functionality is added tothe display. Another advantage is that sagging of the display isprevented. The display will be perceived as stiffer which gives a betterquality perception of the display system.

Also the embodiment shown in FIGS. 4-7 is a ‘book’ display system 1 witha number of parts substantially identical to the number of parts of thefirst embodiment. It consists of a continuous flexible display 2 housedin two housing halves and a support frame, comprising two main displaysupports 3, 4, each located in a housing halve and being connected atboth sides of the system 1 by hinges 5, 6, of a hinge mechanism 7 andeach structurally configured to support a respective portion of theflexible display. As shown in FIGS. 5, 6, 7 the two main displaysupports 3, 4 comprise arms 3 a, 4 a connected with hinges 5, 6respectively. The supports are mutually hingable around their hinges 5,6 between a planar configuration (FIGS. 5, 6) for fixing the flexibledisplay 2 in an open position and a configuration for fixing theflexible display in a closed storage position (FIGS. 4 and 7). Adifference with the first embodiment is the application at the locationof both hinge mechanisms 7 of a torsion spring 17 with legs 17 a, 17 bconnected with their free ends with the arms 3 a, 4 a. Each of thetorsion springs 17 passes with its legs 17 a, 17 b during movement ofthe housing halves between the open and closed position through a planecomprising the axes of the hinges 5, 6 and moves from one to the otherside of this plane. Thus the torsion springs act as part of an overcenter mechanism. The torsion springs 17 also provide spring force viathe arms 3 a, 4 a on the main display supports 3, 4, forcing thesesupports to the planar configuration and via the main display supportson the central display segment 2 a of the flexible display topre-stretch the central display segment 2 a at the open position. Thespring forces of the two torsion springs 17 between the two book halveskeep the book stably positioned in the open and closed positions.

In this embodiment the movement synchronizing coupling comprises a pairof gear mechanisms 18 with teethed segments 19, 20 on both displaysupports 3, 4 which are engaged to each other, enabling a synchronizedrotating of the main display supports at substantially equal butoppositely directed angles and synchronized movement of the additionaldisplay supports 8, 9, 10, 11 and 12 when the two book halves are openedor closed. Due to the coupling between the legs 17 a, 17 b and theadditional supports 8, 9, 10, 11 and 12 the springs 17 also keep thesesupports stably positioned in their position supporting the displaysegment 2 a in the open position of the book halves.

Also in this embodiment of the invention, sufficient space is availablefor the construction of the double hinges 5, 6, two torsion springs 17and the gear mechanisms 18 and for enabling a partial curvature of thedisplay segment 2 a in the closed position without conflicting with therespective main display supports. Preferably in this closed position theadditional support plate 12 facilitates by its stable positioning apre-defined curvature of the display segment 2 a with an advantage forthe lifetime of the display.

In the embodiment shown in FIGS. 8a-8f in a ‘book’ display system 1 thecentral display segment 2 a is supported by additional display supportscomprising a central support plate 33 and two hingeably connecteddisplay support plates 34, 35. The central support plate 33 is used asdual guided hinge part for the two display supports 3, 4 which arecoupled by gears 36, 37. The gears are rotatable around the respectivehinge axis and connected with the respective display support and act asa movement synchronizing coupling between both book halves and enable asynchronized rotating of the main display supports 3, 4 at substantiallyequal but oppositely directed angles and synchronized movement of theadditional display supports 33, 34 and 35. The support plates 34, 35each have a pin 34 a, 35 a that is guided in a slot 3 b, 4 brespectively, in each of the display supports 3, 4 of the device body.These slots 3 b, 4 b guide the movement of the plates 34, 35 in such amanner that in open position of FIGS. 8a and 8b the display segment 2 ais completely supported and in closed position of FIGS. 8e and 8f thecurved display segment 2 a is not obstructed. FIGS. 8c and 8d show anintermediate situation. Preferably in the closed position the plates 33,34 and 35 facilitate by their positioning a predefined curvature of thedisplay segment 2 a with an advantage for the lifetime of the display.

The embodiment schematically shown in FIGS. 9a and 9b shows relevantparts of a ‘book’ display system 1 with a hinge mechanism 39 and maindisplay supports 40, 41. These main supports are hingeably connected viahinges 5, 6 like the supports in the preceding embodiments. The hinges5, 6 are the axle for pulleys or wheels 42, 43 connected to the support40, 41 respectively. The pulleys are guiding a spring or belt 44. Asshown in FIG. 9b the belt is guided on a crossing way such that thecombination of pulleys 42, 43 and belt 44 couples the supports 40, 41for rotation in opposite directions and acts as a movement synchronizingcoupling between both book halves and the additional support plates (notshown). Opening of the left support 40 in FIG. 9a in the direction ofarrow a results into movement of the belt 44 near the pulley 42 in thedirection b, of the belt near the pulley 43 in the direction c and thusin an opening of the right support 41 in the direction d with the samedegree of opening of both supports 40, 41.

The embodiments schematically shown in FIGS. 10 and 11 show alternativesolutions for the synchronized coupling of the book halves in oppositedirections in the embodiment of FIGS. 9a-9b . In FIG. 10 an alternativesolution is shown with a connecting rod 44 between the wheels 42, 43. InFIG. 11 another alternative solution is shown with a connecting belt 45,guided between guiding walls 46 a, 46 b.

In the embodiment shown in FIGS. 12a-12g the display system 1 comprisestwo book halves 50, 51, connected by a hinge mechanism 52 with at bothends parts two hinges 53, 54. The book halves 50, 51 are provided in thehinge area with teeth or extensions 55, 56 with free ends locatedsubstantially halfway between the book halves. An elongated spring 57extends between the end parts of the hinge mechanism 52. As shown indetail in FIGS. 12e, 12f the spring 57 is guided through holes near thefree ends of the teeth 55, 56. As shown in FIG. 12g by way of example,the spring 57 may be configured as a coil spring 57 a or a spring wire57 b. Opening of the book halves 50, 51 in FIG. 12a to the open positionof FIG. 12b results in a synchronized movement of both book halves 50,51 in the direction of arrow e, f respectively shown in detail in FIG.12c and a movement of the spring in the direction of arrow g. Halfwaythe spring moves through a plane 58 comprising hinge axes of hinges 53,54 and expands under its spring force in the direction of arrow g(comparable with the working of an over center mechanism). The spring 57forces via the teeth 55, 56 the book halves 50, 51 to make the samerotation and thus the same degree of opening. The same synchronizationis obtained during the movement from the open position of FIG. 12dtowards the closed position of FIG. 12c in the direction of arrow h inFIG. 12d . In this way the teeth 55, 56 and the spring 57 act as amovement synchronizing coupling between both book halves, which move inthe direction of arrows i and j respectively. In a way not shown also inthis embodiment the additional display supports of the precedingembodiments may be applied, with a synchronized movement due to theirconnection with the movement synchronizing coupling.

The detailed drawings, specific examples and particular formulationsgiven, serve the purpose of illustration only. Furthermore, othersubstitutions, modifications, changes, and omissions may be made in thedesign, operating conditions, and arrangement of the exemplaryembodiments without departing from the scope of the invention asexpressed in the appended claims.

What is claimed is:
 1. A display system comprising: a flexible display;a first case and a second case comprising first extensions and secondextensions, respectively, the first extensions and the second extensionshaving free ends located between the first case and the second case; afirst main display support and a second main display support that areconnected to the first and second cases and support the flexibledisplay; a hinge mechanism that rotatably connects the first and secondcases so that the flexible display is folded in a closed position andunfolded in an open position; and an elongated spring connecting thefirst extensions and the second extensions to provide spring forces onboth of the first and second cases to simultaneously rotate the firstand second cases.
 2. The display system of claim 1, wherein the hingemechanism comprises a first hinge and a second hinge to which the firstand second main display supports are rotatably connected, respectively.3. The display system of claim 2, wherein the hinge mechanism comprisestwo legs connected to both of the first and second main displaysupports, respectively, and wherein each of the two legs rotates about arotation axis that is parallel to an axis of one of the first hinge orthe second hinge.
 4. The display system of claim 3, wherein theelongated spring extends between ends of both of the first and secondhinges.
 5. The display system of claim 1, wherein the elongated springcomprises one of a coil spring or a spring wire.
 6. The display systemof claim 1, wherein the first extensions comprise at least three firstextensions and the second extensions comprise at least three secondextensions.
 7. The display system of claim 1, wherein the firstextensions and the second extensions comprise holes through which theelongated spring is disposed.